The goal of this application is to map the translational landscape of excitatory neurons in response to synaptic activity. My interest in this problem is motivated by the observations that dynamic regulation of translation is crucial for both long term potentiation (LTP) and long term depression (LTD), the two forms of synaptic plasticity thought to underlie the cellular basis of learning and memory. Despite the importance of translational control in synaptic plasticity, only a handful of genes have been studied in this context. As a postdoctoral fellow in Jonathan Weissman's lab, I have developed an innovative approach for translational profiling with subcellular resolution. This technique is based on ribosome profiling, the deep sequencing of ribosome- protected mRNA fragments, invented in the Weissman lab. My immediate goal is to apply the technical and analytical toolkit that I have developed during my graduate and postdoctoral training to explore fundamental questions in neuroscience. The aims of this application are to 1) understand which mRNAs are translated locally in dendrites, and how translation is regulated in the dendritic and somatic compartments in response to elevated or silenced synaptic activity; 2) develop precise genetically encoded tools to facilitate dendritic ribosome profiling and dendritic proteomics; 3) explore the rapid translational changes that occur during LTD and determine which changes drive the electrophysiological response to activity. Having a genome-scale view of the translational response to synaptic activity should generate numerous hypotheses that I will continue to pursue in my independent research group. In order to achieve these aims, I seek interdisciplinary mentored training in neuroscience, gene regulation and cell biology. Towards this end, I have assembled a team of mentors with expertise in: systems biology and genome-scale data acquisition and analysis (Jonathan Weissman), neuroscience, synaptic plasticity and electrophysiology (Roger Nicoll), circuit analysis and activity-dependent signaling (Zachary Knight) and proteomics and genetic interaction analysis (Nevan Krogran). These mentors represent a broad and relevant collection scientific perspectives as well as career perspectives, as it includes both recently hired junior faculty and experienced tenured faculty. This K99/R00 award provides a protected training period in which I will expand my knowledge base in neuroscience, for example by taking the graduate neuroscience course NS201 at UCSF and the intensive Marine Biology Lab Neurobiology summer course. Such training will greatly facilitate my long-term research goals of understanding how neurons respond to synaptic activity with subcellular specificity and how activity-dependent gene expression changes are integrated into a spatially precise response. My long-term career objective is to pursue these research interests as a tenure-tracked principle investigator in an interdisciplinary biology department at an academic research institution.